1. Field of the Invention
The present invention relates to a method and system of collecting and processing signal data. More specifically, the present invention relates to a method and system for enhancing a reflection wave signal in the background of a direct wave.
2. Description of Related Art
To obtain hydrocarbons such as oil and gas, boreholes or wellbores are drilled through hydrocarbon-bearing subsurface formations. The drilling of horizontal or deviated wellbores can create some difficulties of downhole imaging due to bed boundaries or dipping beds that are encountered downhole. To overcome this problem three dimensional borehole profiles have been developed. These three dimensional borehole profiles can change direction along the way.
A well bore drilled through earth formations encounters various geological structures intersecting the borehole. Borehole acoustic measurements can be used to obtain an image of the formation structural changes away from the borehole (Hornby, B. E. 1989, Imaging Near-Borehole of Formation Structure Using Full-Waveform Sonic Data, Geophysics, 54 747-757; Esmersoy et al., 1998, Acoustic Imaging of Reservoir Structure from a Horizontal Well, The Leading Edge, 17, No. 7, 940-946; Li et al., 2002, Single Well Imaging with Acoustic Reflection Survey at Mounds, Oklahoma, , USA: 64th EAGE Conference & Exhibition, Paper P141; Tang, 2004, Imaging Near-Borehole Structure Using Directional Acoustic-Wave Measurement: Geophysics, 69, 1-10; Zheng and Tang, 2005, Imaging Near Borehole Structure Using Acoustic Logging Data with Pre-Stack F-K Migration: 75th Ann. Internation. Mtg.: Soc. Of Expl. Geophys.) provided that the acoustic wave phenomena in the near borehole region are properly understood and utilized.
Data collection arrays, i.e. a collection of more than one single position point data recorders, are used in the collection of a myriad of data. Examples of array collected data include radar, seismic, acoustic, sonar, radio waves, to name but a few. Often the data received and recorded by such arrays can include unwanted signals that intermingle with the desired data and distort the final recordings thereby providing skewed results. Moreover, when dealing with arrays of data recording devices, the time lag between signals of the individual recorders is especially important.
Downhole sensors can be provided with a downhole tool for measuring downhole conditions. The downhole tool can include a sonde insertable within the wellbore as well as any subterranean drilling devices. Also included can be apparatuses for detecting inclination. These measurements are useful to determine hydrocarbons and water presence proximate to the downhole tool. These measurements can also be used to steer a downhole tool. However, the depth that these devices can monitor within the formation is limited and they typically do not provide bed boundary or dipping bed information. One example of a borehole imaging apparatus and method is found in U.S. Application No. 20040158997 (Ser. No. 10/353,330), published Aug. 19, 2004, which is incorporated by reference herein in its entirety.